1. Field of the Invention
The present invention relates to a handling apparatus for handling an object, such as an LSI, when positioning, carrying, placing, or connecting the object with respect to a target, and relates to a test set using such a handling apparatus.
2. Description of the Related Art
Handling apparatuses are used for various purposes, for example, inserting an electronic component (e.g., an LSI) into a socket.
When inserting an electronic component into a socket for electric tests using a handling apparatus, the electronic component has to be precisely positioned with respect to the socket and pressed against the contact electrode of the socket under a uniform pressure. However, the conventional handling apparatus often fails to position the electronic component precisely parallel to the socket, and therefore, fails to achieve a uniform contact pressure. The conventional apparatus overcomes this problem by giving elasticity to the contact electrode to absorb a displacement or offset from the parallel position making use of the deformation of the contact electrode, thereby guaranteeing uniform contact pressure between the electronic component and the socket.
By the way, there is a rapidly growing tendency extending back over recent years toward miniaturization of products and higher performance with increased operation speed has grown rapidly. To respond to this demand, the contact electrode of a socket used for electric tests is also miniaturized, employing a multi-polar structure. In addition, it is desired for the contact electrode to be further reduced in length (for example, up to 0.5 mm), while improving the electric characteristics of the contact electrode, as illustrated in Table 1 below.
However, as the contact electrode is miniaturized, the deformation of the contact electrode inevitably decreases (for example, to 0.1 mm). Accordingly, it is no longer possible for the deformation of the contact electrode alone to correct the size error or the displacement of the electronic component from the parallel position relative to the socket.
Japanese laid-open patent publication 2002-5990 discloses a handling apparatus having a mechanism that retains a vacuum holder for holding an electronic component. The vacuum holder is retained via multiple compression coil springs so as to be slightly movable. The vacuum holder that holds an electronic component moves down toward a socket to bring the electronic component into electric contact with the socket.
The handling apparatus disclosed in 2002-5990 is furnished with a mechanism for adjusting and correcting the displacement or positional offset of the electronic component from the parallel position relative to the socket. Accordingly, even if the deformation of the contact electrode is very small, the electronic component can be fit into the socket and brought into contact with the contact electrode precisely.
However, the handling apparatus with the vacuum holder retained via compression coil springs has another problem. That is, the electronic component held by the vacuum holder often falls off due to vibration of the vacuum holder, and the fragile electronic component is likely to be damaged by the fall. Especially, in the actual electric test, the transport mechanism carries the electronic component by moving the vacuum holder from one test station to another test station. Every time the transport mechanism stops or starts moving, large vibration may occur, which propagates to the electronic component. It is difficult for the handling apparatus disclosed in 2002-5990 to hold and carry the electronic component in a stable manner. If the transport mechanism is designed so as to move slowly and gently to prevent vibration, the electric test cannot be conducted efficiently.
Therefore, it is an object of the present invention to provide a handling apparatus that allows highly precise positioning and electrical contact between an electronic component and the contact electrode with improved stability of the electronic component during the handling.
It is another object of the present invention to provide a test set using such a handling apparatus.
To achieve the object, in one aspect of the invention, a handling apparatus comprises a main unit, a holder holding an object, a retainer that retains the holder so as to be displacable with respect to the main unit, a driving mechanism for driving the main unit to bring the object toward a target, and a latch unit that selectively brings the holder into a latched state, in which the displacement of the holder with respect to the main unit is restrained, or an unlatched state, in which the displacement of the holder with respect to the main unit is not restrained.
If the unlatched state is selected, the fixed state of the holder is released, and the object held by the holder can be displaced. Therefore, the object is well positioned with respect to the target in a flexible manner. If the latched state is selected, the holder is maintained securely with respect to the main unit, and therefore, the object can held in a stable manner.
The retainer retains the holder so that in the unlatched state the holder can be displaced along the X, Y and Z axes of the handling apparatus, and the holder can rotate about its moving axis. One of the X, Y, and Z axes is consistent with the moving axis of the main unit.
This arrangement allows the object to be accurately positioned with respect to the target in the unlatched state.
Alternatively, or in addition, the retainer retains the holder so that the holder can rotate about X, Y, and Z axes of the handling apparatus in the unlatched state. One of the X, Y, and Z axes is consistent with the moving axis of the main unit.
With this arrangement, when the object is pressed against the target, positional offset or inclination of the object from the parallel position relative to the target can be absorbed in the unlatched state.
The retainer utilizes at least one of a mechanical spring, a fluid, a porous elastic material, a gel, and magnetism, thereby allowing the object held by the holder to be slightly movable in the unlatched state.
The holder may be divided into multiple sections, and each section being retained by the retainer with respect to the main unit. In this case, each section is independently displacable in the unlatched state, which can absorb positional offset from the parallel position more efficiently. Consequently, the object can be positioned and aligned more precisely with respect to the target.
The latch unit includes a latching member that is movable between a latched position, at which the latching member is engaged with the holder, and an unlatched position, at which the latching member is disengaged from the holder. At the latched position, stability of handling the object can be guaranteed. At the unlatched position, the object can be positioned and aligned with respect to the target flexibly. The motion of the latching member between the latched position and the unlatched position may include not only linear motion, but also nonlinear motion including rotation, pivoting, and other motions.
Preferably, the handling apparatus further comprises a switching member configured to switch the latch unit between the latched state and the unlatched state based on at least one of a distance between the object and the target, an amount of motion of the main unit, a moving speed of the main unit, and an acceleration of the main unit.
For example, the switching member switches the latch unit from the latched state to the unlatched state before the object comes into contact with the target. With this arrangement, the object can be stably held by the holder immediately before it comes into contact with the target. Upon releasing the latched state, the object can be positioned so as to be precisely parallel to the target.
In the second aspect of the invention, a test set for testing an object is provided. The test set comprises a test unit configured to carry out a test of the object, and a handling structure for transporting the object and positioning the object with respect to the test unit. The handling structure comprises a main unit, a holder that holds the object, a retainer that retains the holder so as to be displacable with respect to the main unit, a driving mechanism for driving the main unit to move the object toward the tester, and a latch unit that selectively switches the handling structure between a latched state, in which the displacement of the holder with respect to the main unit is restrained, and an unlatched state, in which the displacement of the holder with respect to the main unit is not restrained.
The object to be tested is, for example, an electronic component. In this case, the test unit includes a socket having a contact electrode to carry out an electric test for the electronic component. The electric test includes not only testing the operation and characteristics of the electronic component, but also writing data in the electronic component.